Recently, much research has been directed towards the building of networks of distributed wireless sensor nodes. Sensor nodes in such networks conduct measurements at distributed locations and relay the measurements, via other sensor nodes in the network, to one or more measurement data collection points. Sensor networks, generally, are envisioned as encompassing a large number (N) of sensor nodes (e.g., as many as tens of thousands of sensor nodes), with traffic flowing from the sensor nodes into a much smaller number (K) of measurement data collection points using routing protocols. These routing protocols conventionally involve the forwarding of routing packets throughout the sensor nodes of the network to distribute the routing information necessary for sensor nodes to relay measurements to an appropriate measurement data collection point.
A key problem with conventional sensor networks is that each sensor node of the network operates for extended periods of time on self-contained power supplies (e.g., batteries or fuel cells). For the routing protocols of the sensor network to operate properly, each sensor node must be prepared to receive and forward routing packets at any time. Each sensor node's transmitter and receiver, thus, conventionally operates in a continuous fashion to enable the sensor node to receive and forward the routing packets essential for relaying measurements from a measuring sensor node to a measurement data collection point in the network. This continuous operation depletes each node's power supply reserves and, therefore, limits the operational life of each of the sensor nodes.
Therefore, there exists a need for mechanisms in a wireless sensor network that enable the reduction of sensor node power consumption while, at the same time, permitting the reception and forwarding of the routing packets necessary to implement a distributed wireless network.